Mary Clem

As chief clerk for the Statistical Lab at Iowa State University Mary Clem (1905-1979) performed hundreds of thousands of mathematical calculations. She even created a new method, called “zero check,” to catch errors and save statisticians from becoming lost in a maze of math mistakes!

Use your own calculation skills to find your way through these number mazes.

Instructions: Move one vertical or horizontal square at a time, adding numbers as you go. You may visit each square only once. Start at the entrance and reach the exit with a total of exactly 20.

Can you match Mary Clem’s calculating skill?  Click here to download Mary’s Math Mazes and Answer Key.